Department of Entomology, Texas A&M University, College Station, TX 77843-2475, USA.
Pest Manag Sci. 2010 Feb;66(2):147-54. doi: 10.1002/ps.1847.
Helicoverpa zea (Boddie) pyrethroid resistance monitoring programs typically utilize cypermethrin in the adult vial test. Here we investigated if differences in insect growth stage and pyrethroid structure affect resistance ratios and discuss implications for pyrethroid resistance management.
Vial bioassays with cypermethrin, esfenvalerate and bifenthrin were conducted on H. zea third instars and male moths from a susceptible laboratory colony and the F1 generation of a pyrethroid-resistant field population. In the susceptible population, both growth stages were most sensitive to bifenthrin and adults were more sensitive to esfenvalerate than cypermethrin. LC(50) resistance ratios for the larvae and adults of the resistant population were approximately two times higher for bifenthrin than cypermethrin or esfenvalerate.
For the resistant population, vial assays using either growth stage gave similar resistance ratios for each of the three pyrethroids, respectively, proving the adult vial test accurately reflects larval resistance. However, as resistance ratios varied considerably depending on the pyrethroid used, resistance ratio values obtained with one pyrethroid may not be predictive of resistance ratios for other pyrethroids. Our results suggest that carefully chosen pyrethroid structures diagnostic for specific mechanisms of resistance could improve regional monitoring programs.
棉铃虫（Boddie）拟除虫菊酯抗性监测计划通常在成虫管测试中使用氯菊酯。在这里，我们研究了昆虫生长阶段和拟除虫菊酯结构的差异是否会影响抗性比值，并讨论了对拟除虫菊酯抗性管理的影响。
对来自敏感实验室品系的棉铃虫 3 龄幼虫和雄性成虫以及田间抗药性种群的 F1 代进行了氯菊酯、乙氰菊酯和联苯菊酯的管内生物测定。在敏感种群中，两种生长阶段对联苯菊酯最敏感，成虫对乙氰菊酯比氯菊酯更敏感。抗性种群的幼虫和成虫对双苯菊酯的 LC50 抗性比值比氯菊酯或乙氰菊酯分别高出约两倍。
对于抗性种群，使用任一生长期的管内测定均能分别为三种拟除虫菊酯提供相似的抗性比值，证明了成虫管内测试准确反映了幼虫的抗性。然而，由于抗性比值因所使用的拟除虫菊酯而异，一种拟除虫菊酯获得的抗性比值可能无法预测其他拟除虫菊酯的抗性比值。我们的结果表明，选择合适的拟除虫菊酯结构作为特定抗性机制的诊断方法，可以改进区域性监测计划。
